Move ReadFileToString to the base namespace.

chrome/browser/page_cycler/page_cycler_browsertest.cc

Index: chrome/browser/page_cycler/page_cycler_browsertest.cc
diff --git a/chrome/browser/page_cycler/page_cycler_browsertest.cc b/chrome/browser/page_cycler/page_cycler_browsertest.cc
index b2cbe0e2b9243fe235045b1a0a9b47ea0fb7cca2..5e6dbefe070e2f98cf2cc40a3405294afd7b6bed 100644
--- a/chrome/browser/page_cycler/page_cycler_browsertest.cc
+++ b/chrome/browser/page_cycler/page_cycler_browsertest.cc
@@ -90,8 +90,7 @@ class PageCyclerBrowserTest : public content::NotificationObserver,
   // Read the errors file, and generate a vector of error strings.
   std::vector<std::string> GetErrorsFromFile() {
     std::string error_file_contents;
-    CHECK(file_util::ReadFileToString(errors_file_,
-                                      &error_file_contents));
+    CHECK(base::ReadFileToString(errors_file_, &error_file_contents));
     if (error_file_contents[error_file_contents.size() - 1] == '\n')
       error_file_contents.resize(error_file_contents.size() - 1);